package com.arron.interpreter.improve;

//方向解释：终结符表达式
public class DirectionNode extends AbstractNode{
    private String direction;

    public DirectionNode(String direction) {
        this.direction = direction;
    }

    //方向表达式的解释操作
    @Override
    public String interpret() {
        if(direction.equalsIgnoreCase("up")){
            return "向上";
        }
        else if(direction.equalsIgnoreCase("down")){
            return "向下";
        }
        else if(direction.equalsIgnoreCase("left")){
            return " 向左";
        }
        else if(direction.equalsIgnoreCase("right")){
            return "向右";
        }
        else{
            return "无效指令";
        }
    }
}
